Gear drive for centrifugal machines



March 16, 1943. V c. A. dLco'rT GEAR DRIVE FOR QENTRIFUGAL MACHINE9115a, llay 24. 1938 s Sheets-Sheet INVENTOR CHARLES A. OLCOTT BY HISATTORNEYS M 94 c. A. OLCOTT 2,314,285

I GEAR BRIVE FdR CENTRIFUGAL MACHINE S I Filed May 24. 1938 3Sheets-Sheet 2' m5 ll "WNW CHARLES A. OLCOTT BY HIS ATTORNEYS.

III

March 1'6, 1943: A. oLcOf'r 2,314 8 GEAR muvn FOR cEu'raIFueAi. MACHINESFiled llay 24; 1938- :5 sheets-s eet I INVENTOR CHARLES A; OLCOTT BY HISATTORNEYS Patented Mar. 16, 1943 UNITED STATES PATENT OFFICE GEAR DRIVEFOR CENTRIFUGAL MACHINES Charles A. Olcott, West Milford, N. J.Application May 24, 1938, Serial No. 209,780 Claims. 210-71) Thisinvention relates to centrifugal machines for separating solid materialsfrom containing j driving means so constructed that it prevents thecentrifugal machine being operated at a speed in excess of apredetermined maximum speed.

In the drawings:

1 is a view partly in section and-partly diagrammatic of a gear drivingmeans for a single centrifugal machine of a battery in accordance withthis invention, the gear driving means serving to connect thecentrifugal machine to the main driving shaft for the battery;

Fig. 2 is a diagrammatic view of an electric control means for the geardriving means of Fig. 1;

Fig. 3 is an end view of a drum switch used in the control circuit ofFig. 1;

Fig. 4 is a plan view showing the drum switch of Figs. 2 and 3 developedinto the plane of the Fig. 5 form of the control circuit; and r Fig. 6is a View in elevation showing operating parts of the timing means ofthe controlcir cuits of Figs. 2 and 5.

In the drawings there is shown a basket I of a centrifugal machine, themachine being one of a battery driven from a main drive shaft 2 which isoperated by a synchronous electrical motor or other suitable drivingmeans (not shown). To

drive each basket I from the drive shaft 2 there is providedgearingcomprising a gear. casing 4 having openings in which are fittedroller bear ings S and l. Mounted in the bearings B and I and extendingto opposite sides thereof are.

sleeves 8 and 9, carrying bearings Ill, II and I2, in which the shaft 2is rotatably mounted.

Keyed to thesleeve 8 at opposite sides of the,

bearing 6 are a'clutch member l2 and a gear l4 while keyed tothe sleeve9 at opposite sides of g the bearing 5 are a clutch member and a gear58, the gear 58 having a smaller number of teeth thanthe gear I4.Cooperating with the clutch members I2 and it are clutchmembers and is aview similar to Fig. 2 of a modified end of a shaft or rod 12. V

mounted in the tubular shaft 6!] and projects 22, respectively, whichare keyed to rotate with the main drive shaft 2 and are movablelongitudinally thereof, being operated by levers 24 and 26,respectively, to engage and disengage their cooperating clutch membersl2 and I6, respectively.

The levers 24 and 26 are pivotally mounted on the gear casing 4 and areconnected by a link 28 which has a pivotal connection with the lever 26and a pin and slot connection with the lever 24, the lengths of the link28 and the slot therein being such that either pair of cooperatingclutch be engaged and both may be dismembers may engaged but both cannotbe engaged at the same time. To operate the levers 24 and 26 there areprovided cylinders 39 and 32 mounted in extensions of the walls of thegear casing 4 and having pistons therein connected by rods 34 and 36 tothe levers 24 and 26, respectively. Springs 38 and 49, connected to thelevers and cylinders, serve to operate the levers to separate thecooperating clutch members. Pressure for operating the pistons incylinders 30 and 32 is supplied through a pipeline 42 connected bybranch pipes 44 and 45 to the cylinders. Three-Way valves 48 and 50mounted in the branch pipes are operated by solenoids 52 and 54,respectively,

to positions for supplying pressure to the cylin ders and, upon thesolenoids being de-energized,

are returned by the springs 48 and 59 respectively, to positions forventing air from the cylinders.

'The gears 14 and I8 mesh with pinions' 56 and 58, respectively, fixedon a tubular shaft 60 journailed-in a ball bearing 62 fixed in a wall ofthe casing 4. The shaft 68 projects beyond'the casing '4 and at itsouter end has fixed thereon a flange or clutch member 64, the outer faceof which is provided with a friction surface'or in-- serts ti t To theother end of the shaft 60 there are pivotally connected the inner endsof links 66,

the outer ends of which are pivotally'connected' to intermediate pointsof the lever arms 61 of a centrifugally operated means, one end of thearms 5'! having the weights 68 attached thereto while the other endof'the'arms is pivotally connected to the shell or outer race 69 of aball hearing it, the inner race ll of which is fixed on the from theouter end of theshaft 60 sufiiciently'to have fixed thereon a clutchmember. Encircling the shaft i2 and confined between the bearing it andthe .end ofthe shaft '60 is av spring 19 of such strength and under suchcom-';

The rod 12 is slidably pression as to overcome the centrifugal action ofthe weights 69 and hold the clutch member I4 in engagement with theclutch member 64 to be driven thereby until the shaft 68 attains a speedslightly in excess of the speed necessary to rotate the basket I at itsmaximum speed. When the speed of shaft 88 becomes excessive the centrifugal action of the weights 68 overcomes the spring I9, causing the springto be compressed and the shaft I2 operated to separate the clutchmembers 94 and I4.

Fixed to the clutch member 74 are pins I5 which slidably engage inopenings in a flange I8 fixed on the shaft I8 which drives the basket I.A brake drum 88 is secured to the shaft I8 and acting thereon is a brakeshoe 8| operated by the piston of a brake cylinder 82. Pressure foroperating the brake is supplied from the pipe line 42 through the branchpipe 83 and is controlled by a three-way valve 84 operated by a solenoid85. The solenoid 85, when energized, operates valve 84 to supplypressure to the brake cylinder against the action of a spring 88 andwhen thesolenoid is deenergized the spring returns the valve to aposition in which the pressure is vented from the brake cylinder toatmosphere.

The clutch and brake solenoids of Fig. 1 can be energized andde-energized to control the operation of the clutches and brake by meansof electrical circuits such as are shown in Fig. 2. These circuitscomprise a drum switch 88 operated by a reversing electric motor 89through a reducing gear 98. The circuits also include a push buttonswitch 9| spring-biased to open position; a solenoid operated switch 92spring-biased to open position and closed by energization of thesolenoid; solenoid operated switches 93 and 94, spring-biased to closedposition and opened by energization of the solenoids; and a timingswitch 95 which establishes circuits for reversing the motor 89 after apredetermined period of operation. For convenience in distinguishing thecircuits the motor 89 is shown as having separate windings for itsforward and reverse operation. The drum switch 88 is provided withcontacts A, B and C for establishing various connections with thebrushes or contacts d, e, f and g. The contact B is arranged toestablish connection between the contacts at and e throughout amovementof substantially 90 degrees of the switch 88 while the contact Cestablishes a connection between the contacts e and f and the contact Aestablishes a connection between contacts 6 and 9 during limited anglesof movement of the switch 88. The control of the motor 89, however, issuch that the switch 88 moves from a position in which contacts e and gare connected by the contact A through the angle in which contact Bconnects the contacts d and c to a position in which the contact Cconnects the contacts e and f and moves in the reverse direction untilcontact A again connects contacts e and c. There is also provided anormally closed switch 95 arranged to be opened by a centrifugalgovernor 91 or other Speed responsive means driven by suitable means 98from the shaft 88 which drives the basket I in the event'the rotation ofshaft 68 exceeds a predetermined rate.

The timing switch 95 may comprise, as shown in Fig. 6, suitable meansfor closing contacts I23 consisting of a motor ||3 which, through worm5|, drives a gear 53 fixed on a shaft 55' Loosely mounted on the shaft55 is an arm 51 having an extension thereon in which is pivoted a dog orpawl 58 arranged to be operated by a solenoid 2 when solenoid H2 isenergized to engage the pawl with the teeth of gear 53 so that arm 51will be moved with the gear wheel. Loosely mounted on the shaft 55 is anarm 6| on which are the contacts I23. The arm 8| may b positioned atdifferent'distances with respect to the arm 5'! so as to vary the timetaken by the arm 51 to approach and operate the contacts I23, the arm 8|being adjusted manually by means of an arm 63, the end of the arm 83serving as a pointer on a graduated scale to indicate the time requiredfor operating arm 51 to operate the contacts. To operate the contactsthe arm 5'! is provided with a pin 51 arranged to engage and close thecontacts I23 after a predetermined period of operation depending uponthe distance of the contacts from the arm 51 in the initial position ofthe arm 51. After the contacts I23 are closed, the arm 9| moves with thearm 51 until the circuit of motor H3 and solenoid H2 is opened,whereupon the motor I I3 is stopped, solenoid I I2 is deenergized andsprings and I? return the arms 51 and GI to their initial positions asshown in Fig. 6.

When the basket I is at rest the switch 89 will be in the position shownin Fig. 2 and a circuit will be established from one side L of the powerline through lead I88 and switch 98 to contact e, contact A on switch88, contact 9, lead |8| to solenoid 85 of the air brake valve 84 andlead I82 to the other side L of the power line energizing the solenoid85 and causing the brake shoe 8| to be applied to the drum 88 on theshaft I8. Leads I83 and I84 connected to leads I8| and I82 serve toenergiz the solenoid of switch 93 and hold this switch open at this timeso as to keep open the circuit of the solenoid of switch 92 and permitthis switch to be held open by its spring. To start rotation of thebasket I, the switch 9| is closed manually and held closed for a shorttime. Closing switch 9| establishes a circuit from the side L of thepower line through lead I85, switch 9|, lead I89 to a contact of switch92, leads I81 and I88, winding 88F of motor 89, lead I89, switch 94 andlead II8 to the other side L of the power line. This causes motor 89 tooperate switch 88 to shift contact A from contacts e and g and to engagecontact B with contacts at and e. Closing the switch 9| also establishesa circuit through leads I85, I85, HI and H4 for the timing switch 95,energizing the solenoid H2 and causing the motor H9 to start operation.

Movement of the contact A of switch 88 from the contacts e and 9 causessolenoid 85 and the solenoid of switch 93 to be de-energized, permittingthe air brake valve 94 to be operated to vent pressure from the brakecylinder 82 and release the brake and permitting switch 93 to be closedby its spring to complete a circuit through the solenoid of switch 92and leads H5 and H6, energizing the solenoid and closing switch 92 tocomplete a shunt around switch 9| which can now be released. Switch 92now serves to complete the circuit for its own operating solenoid sothis switch is held closed. Engaging contact B on switch 88 with thecontacts d and e completes a circuit from the side L of the power linethrough lead I88, switch 96, contacts e, B and D, lead II'I, solenoid 54and lead M8 to the side L of the power line, energizing solenoid 54 andoperating valve 58 to supply pressure to cylinder 32, operating lever 28against the action of spring 48 to engage the clutch members 22 and I 8causing gear I8 to be driven by shaft 2 and operating through gear 58,sleeve 60, clutch members 54 and I4 and shaft 18 to start rotation ofthe basket I. The ratio of gears I8 and 59 is such that they will drivethe basket at half-speed and the operation of switch 88 by motor 89 istimed to continue contact B in engagement with contacts d and e untilthe basket I' is driven at half-speed whereupon the operation of switch88 moves the contact B from the contacts d and .e, interrupting thecircuit of solenoid 54 and permitting valve 50 to be operated by itsspring 50 to the position for venting pressure from the cylinder 32 toallow spring 49 to operate lever 26 to separate the clutch members 22and I5. The movement of the switch 88 then engages contact with contactse and f establishing a circuit from the side L of the power line throughlead I00, switch 96, contacts e, C and f, lead I I9, solenoid 52 andlead I20 to the opposite side L of the power line, energizing solenoid52 and operating valve 48 to supply pressure to cylinder 30 for theoperation of lever 24 and the engaging of the clutch members 20 and I2.The engaging of clutch members 23 and I2 causes gear I4 to be driven bythe shaft 2 and through gear 56, shaft 6%), clutch members 64 and I4 andshaft I8 to drive the basket at full speed. Engaging contact 0 with thecontacts e and also completes a circuit through lead I2I from thecontact i, solenoid of switch 94 and lead I22 to the side L of the powerline energizing the solenoid of switch 94 and opening the switch. Theswitch 94 being in the circuit of motor 89, opening the switch causesthe motor to stop with the contact C engaging the contacts 6 and theclutch members 28 and I2 maintained in engagement and the basket Idriven at full speed.

Since the closure of switch 9! the motor of to. start operating in thereverse direction, operating the switch 88 to move contact 0 from thecontacts e and f and interrupting the circuit of solenoid 52. the valve48 to be operated to vent pressure from the cylinder 39 and the lever 24to be operated by spring. 38 to separate the clutch members 2!) and- I2so that the basket I is no longer driven at full speed from the shaft 2.Rotation of the switch 88 then brings contact B into engagement with thecontacts (1 and e, establishing a circuit through the solenoid 54 andcausing the operation of lever 26 to engage clutch members 22 and I Asthe basket I is still rotating under its momentum at substantially fullspeed and as the clutch members 22 and I6 and gears I8 and 58 woulddrive the basket I at only half speed, the basket I tends to speed upthe shaft 2 when the clutch members 22 and I6 are engaged and theinertia of the shaft 2 and the other baskets connected thereto exerts abraking action on the basket I which is connected to the shaft throughthe clutch members I6 and 22. Should it happen that a number of basketswere simultaneously changed from being driven by the shaft 2 throughtheir gears It and 56 and were connected to the shaft 2 through theirgears 53 and !8, their momentum might be sufiicient to raise excessivelyand almost instantly the speed of shaft 2 and Ila-energizing solenoid 52permits sible time.

gears I4 and 56. The increase in the speed of the basket excessivelyabove its normal full speed causes the centrifugal action of the weightmembers 68 to overcome the resistance of spring 69 and shift shaft I2 toseparate the clutch members 54 and I2 and disconnect the basket I fromthe drive shaft 2 and prevent the basket I from being rotated at adangerous rate. Rotation of the shaft at an excessive speed would causethe switch 96 to be opened by the centrifugal means 91 and interruptsthe circuit of the solenoid controlling operation of the clutchoperating lever and maintains the circuit open so long as the speed ofthe shaft remains in excess of the predetermined limit.

In the usual operation the speed of shaft 2 is not raised suificien'tlyto cause operation of either of the centrifugal means for any of thebaskets connected to the shaft 2 and the speed of the basket whoseconnection to the shaft has been changed is gradually reduced tohalf-speed by the time the switch 88 has been operated to shift contactB from contacts d and e, interrupting the circuit of solenoid 54 andpermitting the clutch members 22 and IE to be separated, and engagingthe contact A with the contacts e and g to establish the circuits forenergizing the solenoid 85 of the brake valve 84 and the solenoid ofswitch 93, causing the brake shoe 8I to be applied to the drum to stoprotation of the basket I and the switch 93 to be opened. Opening switch93 interrupts the circuit of the solenoid of switch 92 and permits thisswitch to open, thus interrupting the circuits of motor 89 to stopswitch 38 with contact A connecting contacts e and 9, furtherinterrupting the circuit of the solenoid of switch 92 and interruptingthe circuit of the motor H3 and solenoid II2 of the timing switch 95,stopping the operation of the timing switch and permitting return of itsmoving parts to their initial positions.

The arrangement of gear drive and control circuits above describedprovides for building up the speed of the basket from rest to half-speedby means of the lower gear ratio provided, thus greatly lessening theload thrown on the driving motor at each start of a basket and greatlyreducing the wear and maintenance on the clutches and gearing. It alsopermits of maximum acceleration of the basket to half-speed and thebuilding up of the'speed of the basket from half-speed to full speed atthe usual rate of acceleration. ratio in decelerating the basket causesthe basket being slowed to aid in driving the other basket and to reduceto some extent the power consumption of the driving motor during theslowing of the basket from full to half-speed. The centrifugal means 9'?and 68 insure the speed of all baskets being kept below an excessiverate at this time and the timing devices insure the various operationstaking place at the earliest pos- In the modified circuit arrangementshown in Fig. 5 for controlling the energization of the clutch operatingsolenoids and 5s and the brake operating solenoid 35 there is provided apush button switch i341, spring-biased to a position connecting contactsI39 and arranged to be heid in a position connecting contacts Iaii by asolenoid 592 when the solenoid is energized; a switch J32 having a pairof contacts 32 and 355 spring-biased to a position connecting con- '2'tacts I32 by contact I32 and contacts I32 by of any baskets driventherefrom through their Changing to the lower gear contact I32 andarranged to be held in a position connecting contacts I32 by contact I32and contacts 132 by contact I32 by a solenoid I3? when the solenoid isenergized; a pair of switches I35 and I35 arranged to be operated bycentrifugal means I35 and I3?, respectively, which are driven throughsuitable connections I39 from the shaft 65! which drives the basket I.The switches are biased to connect contacts It i and I35 respectively,when the basket I is stopped, and switch 933 is operated when the basketis rotating at slightly less than half-speed to disconnect contacts I3 land connect contacts Hid while switch I36 is operated when the basketspeed is slightly greater than half-speed to disconnect contacts Itt andconnect contacts ISi-fi; a switch I49 spring-biased to closed positionand operated by solenoid I49 to open position when the solenoid isenergized; and a timing switch M2 which closes normally open contactsI43 a predetermined time after the switch is started operating. I I

When the basket I is stopped the switches are positioned as shown inFig. 5 and a circuit is es tablished from the side L of the power line,lead Hi l, contacts ESE) of switch I38, lead Hi5, solenoid 85 of thebrake valve 8d and lead I56 to the other side L of the power line,energizing the solenoid 85 and causing the brake shoe BI to be appliedto the brake drum 8%. To place the basket l in operation, the switch hisis operated interrupting the circuit of the solenoid 85 at the contactsIiil and completing a circuit between the contacts itt Interrupting thecircuit of the solenoid 85 causes the brake to be released andconnecting the contacts I3 3 completes a circuit from the side L of thepower line, lead I44, contacts 530*, leads I43 and I48, solenoid 53d ofswitch I353, lead I49, switch Mil and lead I59 to the side L of thepower line, energizing the solenoid 43B and causing the switch I38 to beheld in position connecting contacts 13d There is also a circuitcompleted through leads id? and I-iI, solenoid i52 and motor it? of thetiming switch and lead it to the side L which starts operation of thetiming switch M2 and a A circuit completed through lead hi7, contactsI3i of switch 53%, leads I55 and I56, solenoid 54, leads #5! and H53,contacts I3? of switch I32 lead ids to the other side L of the powerline ch energizes the solenoid 54 and causes enga ment of the clutchmembers 22 and I and acceleration of the basket I by the low ratio gears2S {it towards half-speed.

As the speed of the basket I approaches halfspeed at approximately 95%of half-speed, for example, the switch I3 5 is operated by thecentrifugal means 5755 opening the circuit of solenoid 54 at contactsE34 and establishing a connection between the contacts lat De-energizingsolenoid E l causes the clutch members 22 and I6 to be separated andconnecting the contacts I 3d establishes a circuit from the side Ll ofthe :power line through lead i ii, contacts itc lead I41, contacts Ii -4lead IEil, solenoid *52, lead lfiI, contacts i iff of switch I32, andlead I62 to the other side L of the, power line, energizing the solenoid52 and causing engagement of the clutch members 29 and I2 and driving ofthe basket 5 by the high ratio gears I l and 55 to accelerate the basketto full speed rotation.

When the basket speed is slightly above halfspeed, at 195% of halfspeed, for example, the centrifugal means I31 operates the contact assto interrupt the connection between the contacts amaze-e:

I36 and to establish the connection between the contacts I36 Operationof the basket at full speed continues until at the expiration of thepredetermined period, depending upon the nature of the material beingtreated, for which the 'time switch I42 was set, the time switch I42operates to close contacts I63 completing a circuit from the side L ofthe power line, lead IE3, solenoid !32 of switch I32, lead IE4, contactsI43 and lead I5 to the other side L of the power line, energizing thesolenoid I32 and operating switch I32 to interrupt the circuit ofsoleniod 52 at contacts I32 and establishing a circuit through lead I65from the side L of the power line, contacts I32 of switch I32, lead I56,solenoid 55, lead I51, contacts I36 of switch I36, lead I66, contactsI32 of switch E32, and lead I62 to the other side L of the power line toenergize the solenoid 54. Deenergizing solenoid 52 causes the clutchmemlbers 2G and I2 to be separated so that the basket is no longerdriven at full speed and energizing the solenoid 54 causes the clutchmembers 22 and E6 to be engaged and the deceleration of the basket tohalf-speed. As the speed of the basket approaches half-speed, but whileit is still slightly in excess of half-speed, the switch I36 is operatedby the centrifugal means it! to interrupt the circuit of the solenoid 53at the contacts i36 and to connect the contacts I36 De-energizing thesolenoid 555 causes the separation of the clutch members 22 and It andthe disconnection 0f the basket I fromthe shaft 2 While the connectionof the contacts ISt establishes a circuit from the side L of the powerline through lead I61, solenoid Mil of switch Idfi, lead I68, contactsI38 leads Hi9 and IE5, switch I43 and lead I54 to the side L of thepower line, energizing the solenoid I46 and operating the switch I iflto open the circuit of the solenoid I3?! which holds the switch I38 inposition connecting contacts Itil De-energizing solenoid I 36 permitsthe biasing spring of the switch I39 to operate the switch, interruptingthe circuit of the timing switch motor 553 and solenoid I52 andestabilishing a connection between the contacts I30 De-energizing thesol noid I52 permits return of the parts of the timing switch to theirinitial positions for the start of a subsequent operation, openingswitch I43 and connecting contacts 1353 establishes a circuit through IM, IS and M6 for the energizing of solenoid and the application of thebrake 8i to stop rotation of the basket. As the speed of the basket isreduced below half-speed, switch 134 is operated by the centrifugalmeans to break the connection be tween the contacts Ita i and establisha connection between the contacts Ii'id Opening the switch I43 opens thecircuits of the solenoid i32 of switch I32 and solenoid ME of switch I40and permits return of these switches to their biasing springs.

"The operation of the gearing with the control circuits of Fig. 5 isessentially the same as with the control circuits of Fig. 2, except thatin Fig. 5 there is the speed controlled switch i34 instead of the switch88 which is operated at a rate such as to allow the required time forthe changes in the speed of the basket i, and while a switch and speedresponsive means corresponding to the switch and speed means W of Fig. 2have not been shown in Fig. 5 it is to be understood such a switch andits associated speed responsive means can be placed so as to open thecircuit of the solenoid 52 of Fig. 5 and operate in the same manner asin connection with the control cricu'its of Fig. 2.

Where, in the claims, reference is made to a timing means forcontrolling the operation of the clutches such expression is to beconsidered as including the clutch controlling means as shown in Fig. aswell as the clutch controlling means as shown in Fig. 2.

What is claimed is: Y

1. In a centrifugal machine, a drive shaft com mon to a plurality ofmachines, a driven shaft, a basket operated by said driven shaft, drivemeans of different ratios for connecting said shafts, slip clutch meansfor selectively rendering said drive means effective to connect saidshafts and timing means for controlling the operations of said clutchmeans, said timing means being constructed and arranged to operate saidclutch means to provide a substantially continuous acceleration of saidbasket to the full speed thereof and to operate the clutch means toconnect said shafts by said drive means of lower ratio for deceleratingsaid basket.

2. In a centrifugal machine, a drive shaft common to a plurality ofmachines, a driven shaft, a basket operated by said driven shaft, drivemeans of different ratios for connecting said shafts, slip clutch meansfor selectively rendering said drive means effective to connect saidshafts, timing means for controlling the operations of said clutchmeans, said timing means being constructed and arranged to operate saidclutch means to provide a substantially continuous acceleration of saidbasket to the full speed thereof and to operate the clutch means toconnect said shafts by said drive means of lower ratio for deceleratingsaid basket and speed responsive means for disconnecting said basketfrom said driven shaft upon overspeeding of said shaft by baskets beingdecelerated.

3. The combination of a series of upright cenugal separators, verticaloperating shafts for said respective separators, a main horizontaldriving shaft, two sets of connections between said horizontal shaft andeach of said vertical shafts serving to drive the respective verticalshafts positively at widely different speeds, and controlling meansoperable to throw said sets of connections for each separator into andout of operation selectively.

4. The combination of a series of upright centrifugal separators, a mainhorizontal shaft for driving all of said machines, and independentdriving mechanisms between said respective centrifugals and said mainshaft, each of said mech anisms being constructed and arranged to driveits respective centrifugal from said shaft at both a high speed and alow speed, each of said mech anisms including a supplemental drivingshaft telescoped on the main shaft and gearing driven by saidsupplemental shaft and through which motion from the main shaft istransmitted to its respective centrifugal, and controlling means foreach separator to utilize either of said speeds at will and to shiftfrom one speed to the other.

5. The combination of a series of upright centrifugal separators,vertical operating shafts for said respective separators, a mainhorizontal driving shaft, two sets of connections between saidhorizontal shaft and each of said vertical shafts serving to drive therespective vertical shafts positively at widely different speeds, bothsets of said connections including gearing and one set serving to drivethe operating shaft at a high speed and the other at a low speed andclutches associated with the respective sets and operable to throw theminto and out of operation selectively.

CHARLES A. OLC'OTT.

